Even worse, some of the stone buildings in the streets started crumbling apart before they even got hit by Drogon's fire.
I mean they could try and explain it away with the blast-wave of the fire being powerful enough to just knock down stone buildings, but how the fuck are so many characters just perfectly fine after being in the direct vicinity of a flaming deathray of doom that even makes buildings explode 5-10m away from its flames?

I'm willing to grant them blowing up the wall at winterfell since Viserion may not have used normal dragon fire or was boosted up by the NK's magic or some shit. Not to mention that those walls were ice-cold and the stonework likely already a bit compromised and moist. So it could make sense that a sudden rise in temperature would cause enough steam to build up to force an explosion like we saw.